This invention relates in general to vehicle seats, and in particular to a power seat adjuster using a single motor and a transmission assembly to move the seat in 6 separate axes.
Most passenger vehicles include seats, such as driver and passenger seats, which are adjustably mounted on the floor of the vehicle. It is becoming increasingly common to provide power actuated seat adjusters for adjusting the seat position relative to the vehicle floor. A typical power seat adjuster can be operated to adjust the seat in a fore and aft direction and a generally vertical or elevational direction. Generally, power seat adjusters control the elevation of the front and rear portions of the seat bottom separately. Thus, the typical power seat adjuster can be operated to adjust the seat in generally three axes: 1) fore and aft; 2) front elevation; and 3) rear elevation.
The fore and aft axis corresponds to the generally horizontal longitudinal direction relative to the vehicle, and generally moves the seat closer or farther away from the steering wheel and operating pedals of the vehicle. To allow fore and aft adjustment, vehicle seats typically include track mechanisms having a pair of sliding tracks which permit sliding movement of the seat relative to the vehicle floor. An upper track member is attached to the seat bottom, and a lower track member is mounted on the vehicle floor. A power mechanism driven by an electric motor moves the upper track member relative to the lower track member, thereby moving the seat bottom in the fore or aft direction.
The mechanisms which control the elevation typically include an electric motor and a crank or sector gear for upwardly or downwardly moving the seat bottom. Although the function of the mechanism is to move the seat portions in a vertical direction or axis, some mechanisms move the seat portions in an arcuate path corresponding to a rotating member. Typically, there is an electric motor and gear mechanism for each of the front and rear elevational controls. Thus, conventional power seat adjusters typically include three separate electric motors for controlling the three seat axes. Although the use of three separate motors has been found effective in controlling the position of the seat, the cost of the motors is relatively expensive and increases the weight of the seat.
This invention relates to a powered seat adjuster for a vehicle seat. The vehicle seat assembly includes a motor coupled to an output shaft. At least two driven shafts are each operable between three operating modes. The three operating modes are a stationary mode, a first rotational direction, and a second rotational direction. A transmission assembly connects the driven shafts to the output shaft. The transmission assembly is operable to control each of the driven shafts in any one of the three operating modes when the output shaft rotates in the first rotational direction.